1. Field of the Invention
The present invention relates to an image output apparatus, a history management method, and a history management program.
2. Description of the Related Art
In recent years, business enterprises have had to take measures to prevent leakage of business information they handled. Electronic documents, which are document data such as image files and document files, are extremely convenient for information exchange but are highly risky for leakage of information due to their ease of distribution. In this regard, there is known an application for use for creation of electronic documents, which makes it possible to set in detail the authority to access electronic documents.
For example, Japanese Laid-open patent publication no. 2004-240571 discloses a document access control method in which a document stored in a document DB (database) is read out for output via an operation/perusal unit in response to an access request inputted via the operation/perusal unit. This document access control method uses a rule DB in which rules including conditions for readout of documents stored in the document DB are set on a document-by-document basis. Each document stored in the document DB is read out for analysis in accordance with an access request, whereby unified control of accesses to documents in the document DB can be achieved.
In the case, for example, of electronic PDF (portable document format) documents, access authority can be set not only for the purposes of referencing and changing the electronic documents but also for the purposes of printing the electronic documents and setting print specifications. Coordination with a user authentication system permits more detailed settings in respect of users of the electronic documents.
As an example of collective management of information on authority to access electronic documents, there is known Adobe Policy Server (registered trademark) using a server which is on a network and is provided with a database for use for management of authorities to access electronic documents or the like. The Adobe Policy Server provides a consistent dynamic policy for electronic documents in designating users and usage methods of electronic documents, thereby realizing safety electronic document management. In particular, the security policy can be changed by a creator of electronic documents even after the electronic documents are distributed, making it possible for a manager to carry out the management and monitoring of electronic documents irrespective of wherever the electronic documents are present. Furthermore, an offline policy can be set to provide the security policy even in unconnectable condition. As a result, access control can be implemented at user level and can be carried out during the time the server is offline.
Furthermore, there is provided a function of enabling the manager to perform tracking of an operation history of the managed electronic documents (which are the documents to which the security policy is applied by the Policy Server). The Adobe Policy Server is capable of retaining an access history that indicates what has been made by whom and when. Therefore, tracking can be performed if document leakage is caused by some trouble.
With the document access control method disclosed in the above described Japanese Laid-open patent publication no. 2004-240571, access restriction can be designated even during the time an access management server or a network is in offline or shut down. However, in the case of a print or copy operation being made, a document is outputted as hard data, which makes it difficult to carry out tracking of the outputted data. In addition, the offline policy does not always have an authority lower than user's policy, and thus there is a possibility of permitting a user to carry out an operation beyond user's access authority.
With the document access control method disclosed in the above described Japanese laid-open patent publication no. 2004-240571, it is possible to perform collective management and monitoring of restriction of access to managed electronic documents. In that case, however, a dedicated application program must be used and electronic documents must be compatible with an application-specific format. Therefore, this method is not applicable to non-electronic data such as paper documents of different format nor to image format data (such as bit-map data) converted from data, which has a format processable by the dedicated application, when the data is spooled into a hard disk of a copy machine or the like.
Although the Policy Server is capable of retaining an access history indicating operations performed by terminal apparatuses on managed electronic documents, only file operations performed via the dedicated application can be recorded in the access history. In a case where a managed electronic document is operated by a copy machine or the like not installed with the dedicated application, therefore, no access history can be left, making it impossible to manage the entire history of accesses to the documents.
Under these circumstances, collective access management and tracking of history of accesses to data such as paper data other than electronic data have not been realized, which can be performed as with the case of electronic data. Thus, improvement in the security level has been demanded.